Decelerating and stopping device for conveyor fed sheets



Aug. 20, 1957 P. HEIMLICHER DECELERATING AND STOPPING DEVICE FOR CONVEYOR FED SHEETS- Filed Sept. 9, .1953

United States Patent DECELERATING AND STOPPING DEVICE FOR CGNVEYOR FED SHEETS Paul Heimlicher, Bern, Switzerland, assignor to Maschinenfabrik Winkler, Fallert & Co. A. G., Bern, Switzerland Application September 9, 1953, Serial No. 379,222

Claims priority, application Switzerland September 29, 1952 3 Claims. c1. 271-46) The present invention relates to continuously operative mechanism for successively stopping individual sheets being fed on a conveyor, each sheet being smoothly decelerated.

After stoppage, each sheet is withdrawn from the path of travel of the succeeding sheet. During stoppage, the sheet may be acted upon by a folding device or other suitably synchronized mechanism.

It is known in rotary printing machines to use folding mechanisms provided with devices whereby the paper sheet to be folded along a fold line extending parallel to the feeding direction of the paper, each sheet being conveyed towards fixed abutments at the running speed of the machine in order that each successive sheet may be stopped by the abutments for further conveying in another direction in order to discharge them.

Such folding mechanisms have the disadvantage that in the case of high speeds the paper sheets are abruptly stopped by the stationary abutments whereby they are likely to become damaged, torn or crumpled.

In order to avoid the disadvantages referred to, according to the invention there is incorporated in front of the stationary abutments at least two movable or rotary abutments which retard and progressively decelerate the running speed of the paper sheets to be folded along their running direction, while the stopping of the remanant speed is left to the known stationary stop abutments.

The speed of the movable or rotary decelerating abutments may be so chosen by the shape and dimensions of the same, for instance by the provision of projections or cam surfaces, that the movable or rotary abutments have a lower speed than the paper sheets. The shape and dimensions of the movable or rotary decelerating abutments may also be such that when the paper sheet strikes against the abutments there is initial equality of speed, and the speed of the abutments, and therewith also that of the paper sheet, after striking is decelerated and progressively reduced to Zero.

An illustrative embodiment of the invention is shown in the accompanying drawing. In the drawing, however, only a single decelerating abutment is shown. In practice, there will be a series of such decelerating abutments which are spaced apart and which extend transversely across the full width of the paper sheet for engagement with its leading edge.

Referring to the drawing:

Figure 1 is a side elevational View, partly in section, of a fragment of a folding machine embodying the sheet decelerating and stopping mechanism of the present invention.

Figure 2 is a fragmentary plan view showing one of t as indicated by the arrow, upon continuously moving endless conveyor belts 2. The conveyor belts 2 pass around pulleys 3. A series of decelerating abutment elements 4, is mounted on a revolving cylinder 5. Each of the abutment elements 4, of which a single one is visible in Fig. 1 and is illustrated in Fig. 2, is shaped in the form of a bent finger which may pass freely upwardly between the conveyor belts 2 for engagement with the leading edge 6 of the moving paper sheet 1.

A sprocket wheel 7 is fixed to the cylinder 5 to drive the same in synchronism with other mechanisms of the folding machine. An endless drive chain 8, of which only a portion is shown in the drawing, passes over the sprocket wheel 7 and is powered by connection to some suitable continuously operating power driven portion (not shown) of the folding machine. The cylinder 5 and sprocket wheel 7 are revolubly mounted on a stationary rod 9 secured by a nut 10 to an aflixed arm 11 of the machine frame. Leftward travel of the sheet 1 is positively limited by engagement with fixed stationary abutment elements 12 of which only a single element is visible in Fig. 1 of the drawing.

The folding machine comprises a vertically movable folding knife 14 which acts upon each sheet after it has been stopped by the stationary abutment elements 12. After being folded in conventional manner by the folding knife 14, the paper sheets 1 are removed transversely of the original feeding direction of the conveyor belts 2 by further conveying mechanism including a roller 15.

Figure 3 shows a modified form of decelerating abutment element in the form of a cam member designated generally 16 mounted for rotation with the cylinder 5. The cam member 16 has a cam surface 17 in the form of an Archimedes spiral.

As shown in the drawing, when using either the bent finger type of abutment element 1 or the spiral cam type of abutment element 16 (Fig. 3), the leading edge of the paper sheet 1 is first engaged by a surface which has a velocity component in the direction of sheet feeding which is equal to the velocity of the sheet at the instant of initial engagement. The line of engagement between the leading edge of the sheet and the decelerating abutment element is continuously shifted along the surface of the abutment element so that it has a progressively reduced velocity component in the direction of travel of the sheet edge until the engagement ceases. When engagement ceases, the component is substantially zero so that the sheet is effectively stopped as it reaches the stationary abutment elements 12. In this way the sheet is not damaged by striking the stationary abutment elements 12 at full speed.

With the bent finger form of decelerating abutment element 4, the cam surface extends along its inner side from the crook of the finger to its free tip, the tip of the finger moving substantially vertically as it disengages the leading edge 6 of the sheet 1 so that the sheet 1 is substantially stopped as it engages the stationary abutment elements 12.

With the Archimedes spiral form of cam surface 17, the radius from the line of engagement between sheet 1 and cam surface 17 to the rotational axis of cam member 16 decreases progressively so that a similar eifect is obtained.

While I have shown what I believe to be the best embodiments of my invention, it will be apparent to those skilled in the art that many changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. A device for stopping the travel of spaced sheets carried on a continuously moving conveyor in a predecessive leading edges of said sheets, said cam surface being shaped so as to have substantially the same velocity as a sheet edge at the time of initial engagement therewith at the line of engagement therebetween, and so that said line of engagement is shifted on said cam surface as it rotates so as to have a progressively reduced component of velocity in the direction of travelof said sheet edge until said engagement ceases, at which time said component is zero andsaid sheet is substantially stopped.

2. A device as set forth in claim 1, in which said c surface on said rotating abutment element is in the shape of an Archimedes spiral.

3. A device according to claim 1, in which said rotating abutment element is shaped in the form of a bent finger, said cam surface extending around the inner side of said finger and terminating at its tip.

References Cited in the file of this patent UNITED STATES PATENTS 212,998 Spalckhaver Mar. 4, 1879 

